The invention relates to a device for positioning objects in a desired position.
Devices of this type are generally used in installations with transport systems, for which the objects must be in predetermined desired positions for intake, so that they can be processed manually or by a machine.
One fundamental problem with these arrangements is that objects not only must be positioned with the highest possible precision in the predetermined desirable positions, but that the objects must also be clearly identifiable to avoid confusing the objects.
Examples of this are machines used to perform analyses of blood samples. The blood samples are contained inside individual sample tubes, which are supplied successively to the blood-analysis machine. A sample is typically removed from the tube inside by inserting a needle through the seal on the sample tube and is then analyzed.
Blood-analysis machines of this type have a high rate of throughput, so that a large number of sample tubes per time unit are supplied to the machine. One critical requirement for performing the analyses is that the individual sample tubes are clearly identifiable and the analyses can be assigned to the respective sample tubes. Confusing the individual samples could lead to a misdiagnosis for the patient from whom the blood sample was taken and could ultimately endanger the patient.
To avoid risks of this type, sample tubes are typically provided with unambiguous markings that can be identified by the operating personnel when performing the blood analysis. To be sure, confusing of the individual blood sample tubes can be avoided in this way. However, performing the blood analyses and, in particular, the transport of the sample tubes to the blood-analysis machine must be monitored by operating personnel. Apart from the fact that human error can still result in mistakes when assigning completed analyses to the associated samples in the sample tubes, plants of this type require a high number of personnel.
It is therefore the object of the invention to provide a device that ensures an exact, automatic positioning of objects, wherein a clear identification and tracking of the objects is simultaneously ensured as well.
The device according to the invention for positioning objects in a desired position achieves the above object with an optical sensor, comprising a transmitter for emitting light rays, a receiver for receiving light rays and an evaluation unit. The desired position is scanned with the aid of the transmitted light rays. The device is provided with at least one holding device in which a predetermined number of objects are stored in predetermined slide-in positions. Each slide-in position is characterized with a position mark. The device furthermore comprises a transport system for moving the holding device relative to the optical sensor. The holding device is stopped as soon as the position mark of a slide-in position for a predetermined object is detected by the optical sensor, wherein the respective object can be identified by the sensor through object marks.
The fundamental advantage of the device according to the invention is that the object not only can be positioned precisely in a desired position by the optical sensor, but the optical sensor also ensures an unambiguous identification of the objects. At the same time, the objects are also clearly assigned to the slide-in positions in the holding device.
As a result of the identification of the objects, a confusing of the objects is prevented with high certainty. In addition and owing to the clear assignment of the objects to the slide-in positions in the holding device, an exact localization and tracking of the individual objects within the conveying system is possible as well.
One particularly advantageous embodiment of the invention provides that the device is a component of an arrangement for analyzing blood. The arrangement comprises a blood-analysis machine, of which one component is a sample-taking device with needle. The objects are sample tubes, closed off with a seal, which contain blood samples. To remove samples from the sample tubes, the needle is inserted through the seal into the inside of the respective sample tube.
According to the invention, the sample tubes are supplied automatically to the needle, wherein the individual sample tubes are supplied successively to the sample-taking device, in sample holders that form holding devices. The sample tubes are inserted into slide-in positions in the sample holders.
Respectively one position mark is arranged on these slide-in units, which consists of a position barcode and two reference line elements. The number of the slide-in unit and thus its position within the conveying system is encoded in the position barcode. In addition, an object mark designed as object barcode is respectively arranged on the sample tubes.
The reference line elements form a target mark, which serves to position a slide-in unit in the desired position, in which the needle is arranged. The scanning range for the optical sensor during the positioning in the desired position is advantageously selected such that only the position marks at the slide-in units are detected, but not the object marks.
As soon as a slide-in unit has been positioned completely in the desired position, the slide-in unit position is determined in the device through detection of the position barcode. Following this, the scanning range of the optical sensor is increased, so that the object barcode is also detected. Not only is it possible to clearly identify the sample tubes and their content in the process, but also the assignment to the respective position barcode. Thus, an unambiguous localization of the sample tube within the transport system is ensured as well.
Once the slide-in unit is in the desired position, the needle of the sample-taking device is inserted into the respective sample tube and a sample is removed from the sample tube for performing an analysis. The analysis results are stored together with the information contained in the associated position barcode and the object barcode, so that the analysis result can be assigned clearly.
The transport of the sample tubes to the sample-taking device, as well as the removal of a sample from the sample tube all occur automatically and without use of personnel.